Novel terbium-zircon yellow pigment

Kar, Jitendra Kumar; Stevens, Ron; Bowen, Chris R.

doi:10.1023/b:jmsc.0000040086.92465.50

Cited by 10 publications

(2 citation statements)

References 6 publications

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“…It should be added that doped synthetic ZrSiO 4 of various colouration is used as high-temperature stable and chemically inert pigments. These include, for instance, yellow Pr 3+ -doped ZrSiO 4 (Stiebler et al, 1992;Del Nero et al, 2004), 'lemon'-yellow Tb 3+ -doped ZrSiO 4 (Kar et al, 2004), blue V 4+ -doped ZrSiO 4 (Demiray et al, 1970;Niesert et al, 2002;Pyon et al, 2011) and pink-to-red Fe-doped ZrSiO 4 (Cappelletti et al, 2005). It is, however, well known that the colours of natural zircon have different causes than those of the synthetic pigments, the latter of which contain dopant levels several orders of magnitude above the concentrations of the same elements in natural zircon.…”

Section: Introductionmentioning

confidence: 99%

Blue Zircon from Ratanakiri, Cambodia

Zeug¹,

Nasdala²,

Wanthanachaisaeng³

et al. 2018

Journ of Gemm

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Zircon from Ratanakiri Province, northeastern Cambodia, is well known in the gem trade for its vivid blue colour that results from heat treatment. The untreated brown material turns blue under reducing conditions at ~900-1,000°C. Ratanakiri zircon is characterised by remarkably low contents of trace elements. In particular, the actinides have low concentrations (e.g. approximately 120 ppm U and 95 ppm Th). Together with the very young age of the zircon (<1 million years [Ma]), this results in an extremely low self-irradiation dose, which in turn is in agreement with its non-radiation-damaged, nearly perfectly crystalline state. The heat treatment, therefore, does not result in detectable changes in the zircon's structural state. The cause of the blue colour, presumably related to a valence change upon heating in the reducing environment, is still under debate. The absorption of the treated Ratanakiri zircon is decidedly different from that of blue U 4+-doped and blue V 4+-doped synthetic ZrSiO 4. Absorption spectra show a strongly pleochroic band at 18,200-13,000 cm-1 (corresponding to ~550-770 nm wavelength) that is clearly responsible for the treated blue colour; however, its assignment remains unresolved.

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Section: Introductionmentioning

confidence: 99%

Blue Zircon from Ratanakiri, Cambodia

Zeug¹,

Nasdala²,

Wanthanachaisaeng³

et al. 2018

Journ of Gemm

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“…Equation (1) 18 given below has been used to calculate the weight fraction of the unreacted zirconia present in the mixture It is important to note that the mass absorption coefficient for ZrO 2 (275) and ZrSiO 4 (176) has been calculated by using the equation ( 2) 22 given below…”

Section: Calculation Of Weight Fraction Of Unreacted Zromentioning

confidence: 99%

Effect of cerium oxide on colour hue of praseodymium–zircon yellow pigment

Kar¹,

Stevens

Bowen

2007

Advances in Applied Ceramics

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The influence of cerium oxide on the colour hue of the praseodymium-zircon yellow pigment is presented in the present paper. A variety of pigment compositions were prepared by systematically altering the cerium to praseodymium oxide ratio. After milling of the raw materials the prepared powders were calcined at various temperatures for 2 h soaking times. Orangeyellow colour products were observed in each case. Colour and reflectance measurements were carried out using a spectrophotometer in order to optimise the pigment powders in terms of composition and calcination temperature. Structural characterisations on the optimised powder sample were carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM). X-ray diffraction analysis indicated that zircon was the major phase with traces of unreacted zirconia. From SEM, growth of the tetrahedral zircon crystals and the presence of small amount of unreacted zirconia were observed, which were in a good agreement with the results obtained from XRD. The average particle size of the sample after grinding for 1 h was found to be 12 mm. Finally, as a demonstration of the stability of the pigment, an orange-yellow glaze tile was manufactured when the pigment powder was applied in the commercial unleaded transparent glaze.

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